Project Summary/ Abstract While it is established that screening reduces cancer-specific mortality for breast, cervical, colorectal and lung cancer, screening benefits are only realized through timely follow-up of abnormal screening results. Failure to receive appropriate diagnostic testing undermines the benefits of screening, and violates the trust that patients place in their providers and health systems. Cancer screening is often initiated in primary care settings but requires complex care transitions with other providers who either perform the test or evaluate the result. Often the transition from screening to diagnostic evaluation requires a transfer of role/ responsibility between primary and specialist care. Incomplete follow-up of abnormal cancer screening tests represents an ongoing challenge for primary care providers (PCPs) with barriers to follow-up at the individual (patient, provider), team, and health system levels. We propose to develop, implement, evaluate and disseminate a health information technology (IT)-enabled, multilevel, stepped care intervention grounded in primary care, mFOCUS (multilevel FOllowup of Cancer Screening), to promote appropriate follow-up of abnormal breast, cervical, colorectal and lung findings. We will develop and implement mFOCUS at 40 primary care practice sites affiliated with three primary care networks. Key mFOCUS components include: system design to promote identification and tracking through an electronic health record (EHR)-integrated population management platform with education to promote culture change around the management of abnormal results; use of individual patient and PCP reminders and tools; and a stepped-care team-level enhancement with increasing intensity of contact (i.e., administrative outreach, patient navigation). A 4-arm cluster randomized controlled trial (RCT) of 6,400 individuals who are due for follow-up of an abnormal screening result will allow examination of the marginal and cumulative effectiveness of the multilevel components. Our primary outcome will be receipt of follow-up evaluation, pre-defined by cancer type and abnormality, within 120 days of becoming due for follow-up. Secondary outcomes will assess multi- and cross-level outcomes, such as patient-reported knowledge of their test result and need for follow-up and satisfaction with the care provided by their PCP. Finally, we will study the reach, adoption, implementation and maintenance of mFOCUS using patient, provider and health system surveys and qualitative data to examine barriers and facilitators. mFOCUS builds directly upon relevant conceptual models and the team's prior experience in comprehensive cancer screening and prevention, primary care population management, health IT supported stepped care interventions, patient navigation, and our proven ability to translate the results of such research into clinical practice. This type of multilevel intervention will likely increase as payers and health systems take responsibility for population health through new care financing and delivery models.